The invention relates to a method for forming a honeycomb-shaped core, which is suitable for being included in a honeycomb panel for example, wherein webs or plates of deformable material, in particular cellulose material such as, for example, paper or cardboard, are provided with a number of parallel glue strips and then bonded onto each other and pressed, wherein the glue strips for two plates which possibly originate from said webs, to be successively mounted onto each other, are disposed in a laterally mutually staggered manner, in order to enable the formation of honeycomb cells when the strips which are cut from a number of plates glued to one another are pulled off each other. Generally, for reasons of efficiency, the honeycomb cells have adhering sides which are smaller than the bridging sides of the cells which extend between the plates or strips.
If a large number of plates, for instance 200, are bonded to one another in a stack in this manner, this stack is pressed together and is then cut into transverse bands. These stacks of bands each form a honeycomb core, which, after having been drawn out can, for example, be included in the inner door of a house.
Applying the glue, such as potato starch glue, takes place in a cold state with the help of glue rollers which rotate through a glue bath and transfer the desired quantity of glue onto the plate led past. The glue roller is provided with ribs extending in circumferential direction, which are spaced at a distance from one another which corresponds to the desired lateral distance between the glue strips which are to be applied to the plate.
Applying glue strips preferably takes place in such a way that for two plates which originate or otherwise from respective webs and which are to be mounted onto each other, the glue strips of the one plate will be disposed in a laterally staggered manner with respect to the glue strips of the other plate. This is achieved either by shifting successive plates laterally over the desired mutual distance, use being made of a stationary glue roller, or by using two glue rollers mounted in parallel processing paths or consecutively in one processing path, the ribs or comparable glue contact means of which being arranged over that distance in a laterally mutually displaced manner.
When carrying out the known method it has appeared that glue remains on the ribs or comparable means and on the glue roller, owing to which the glue contact area with the webs or the plates increases in the course of time, so that the glue strips get wider and/or more irregular. If this is to be avoided, then regular cleaning of the glue rollers is necessary, which entails a loss of production time and increases labour costs.
The glue strips have a lateral dimension such that they glue successive plates onto each other along the complete adhering sides of the hexagonal cells, for instance with a dimension of 12 mm for honeycomb cells having a distance between opposite adhering sides of 25 to 37 mm in the honeycomb core to be formed. As a consequence of the manner of applying the glue, the glue strips are, however, irregular and the width thereof varies within a range of 10-17 mm. Because of this the cells too will be irregularly shaped and more plate material will be needed for a honeycomb having a desired length dimension. Because of the glue sticking to the ribs, successive plates and the strips cut from them will be adhered to one another over larger areas in a stack, forming a honeycomb core, as a result of which the achievable stretched a length of that stack will be reduced and the efficiency will consequently be decreased. Moreover, glue is spilled.